In olden times, it was believed that to look into the future was to tempt the wrath of God. Scrying in standing pools of water, or casting rune sticks (they were not originally stones,) even reading the guts of some slain animal were all seen as dangerous. For some reason, people were afraid to be prepared for some possible future. They also misunderstood what most divination was really for.
When I read the runes, or put down tarot cards, I am not trying to see the future. The future can change in an instant by making a decision, so there is no true way to know what the future will definitely be. What I am looking for is a guide post: tell me where I am at this moment, from the decisions already made, the actions already done. Tell me where I am, that I might see more clearly, and make decisions that will take me where I need to go, even if it isn't where I think I want to be. That is the hardest thing to deal with when doing readings for someone else. What will that person think of what I am telling him? I often ask the person to ask the question of the cards or stones in silence. If I tell them what it is I see without knowing what they were asking, then the interpreting is up to him/her.
I have always been bothered by a reader who asks questions rather than giving answers. I have even played mind games with one or two of them to see if that one or the other could really tell me what the reading had to say. Only one or two have proven to be straight forward. To them I return when in a dilemma I cannot see clearly for myself.
I am a caster of stones. There are many forms of reading. Personally, I would say stick to the original decks of tarot and runes, and avoid all this "new age" stuff (cards based on crop circles?! If they think they know what was meant by those drawings, they should do more with it than that!). Yet, you yourself will have to see what talks clearest to you. Everyone is different. I never felt really at ease with tarot, but the stones talked to me from the first time I handled them.
You'll know when it is right.